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2018-10-17

What does a magneto rheological fluid contain?

What does a magneto rheological fluid contain?

Magnetorheological (MR) fluids are a class of smart materials whose yield stress increases considerably in the presence of externally applied magnetic field. These fluids are composed of soft, spherical, magnetic particles whose diameters range from 0.01 to 20 µm dispersed in an organic liquid.

What is Magneto Rheostatic fluids?

A magnetorheological fluid (MR fluid, or MRF) is a type of smart fluid in a carrier fluid, usually a type of oil. When subjected to a magnetic field, the fluid greatly increases its apparent viscosity, to the point of becoming a viscoelastic solid. MR fluid is different from a ferrofluid which has smaller particles.

Which one of the following is an example of magneto fluids?

liquid such as mineral, silicone oils, kerosene, water. liquid such as mineral, silicone oils, kerosene, water.

Which of the following can be used as base fluid in magnetorheological fluid?

Commonly used base fluids are mineral oils, hydrocarbon oils, and Silicon oils. For this technology to be useful, the suspended particles should be affected by the magnetic field quickly. For this, magnetizable metal particles are used.

How do you make electro liquid fluid?

A simple ER fluid can be made by mixing cornflour in a light vegetable oil or (better) silicone oil. There are two main theories to explain the effect: the interfacial tension or ‘water bridge’ theory, and the electrostatic theory.

Is Mr fluid a Newtonian?

When a magnetic field is not present an MR fluid behaves like a Newtonian fluid. When a magnetic field is present, the MR fluid shows a characteristic of Bingham fluids. For an MR fluid, the yield stress can be controlled, increasing or decreasing with the strength of the magnetic field as described in Eq.

How does Mr fluid work?

MR Fluids. MR Fluids consist of magnetic (typically iron) particles in a carrier fluid. In the absence of a magnetic field applied across the gap the fluid occupies, the fluid flows freely or allows free movement. Upon application of a magnetic field, the particles align like chains with the direction of the field.

What is Magneto Rheostatic used for?

Applications and uses: The most common form of MR fluid consists of tiny iron particles suspended in oil, while ER fluids can be as simple as milk chocolate or cornstarch and oil. ER- mainly been developed for use in clutches and valves, as well as engine mounts designed to reduce noise and vibration in vehicles.

What are different types of rheological fluids?

In rheological measurements, three types of flow are often applied: the steady-state shear, dynamic shear, and external flow.

What is magnetorheological effect?

Abstract. Magnetorheological elastomers are composite materials made of micron sized magnetic particles embedded in an elastomer matrix. By applying a magnetic field, the Young’s modulus of those materials can be controlled, which leads to the so-called magnetorheological effect and defines them as a smart material.

What are Mr fluids used for?

Magneto rheological (MR) fluid technology has been proven for many industrial applications like shock absorbers, actuators, etc. MR fluid is a smart material whose rheological characteristics change rapidly and can be controlled easily in presence of an applied magnetic field.

Why are additives known as thixotropic agents added to magnetorheological fluids?

Thixotropic additives such as sodium stearate and lithium stearate (Olabi & Grunwald, 2007) have been used to enhance the sedimentation stability of the carrier fluid. Particle sizes also determine stability of the magnetorheological fluids to a large extent.

Which structure is formed in smart fluids?

Smart fluids are typically composed of a suspension of small particles dispersed in a dielectric fluid (oils, polyethers) and the application of suitable stimulus (electrical or magnetic) increases its resistance to flow [31] .

Which is used as stabilizing additives in magneto rheological finishing?

In this research work, magneto rheological samples are prepared with two different carrier oils (Honge and Castor) independently. Both the samples are mixed and prepared with same concentration of iron particles. In order to reduce the sedimentation fine lithium grease is added as stabilizer for both samples.

How is the material removed in magnetorheological finishing process?

The nonmagnetic abrasive particles are closely surrounded by the carbonyl iron particles (CIPs) chains. These abrasives which are in contact with the workpiece surface are called as active abrasives and are responsible for the material removal during the rotation of a finishing spot of MRP-fluid on workpiece surface.

What is magnetorheological Abrasive Flow Finishing?

A new precision finishing process called magnetorheological abrasive flow finishing (MRAFF), which is basically a combination of abrasive flow machining (AFM) and magnetorheological finishing (MRF), has been developed for nano-finishing of parts even with complicated geometry for a wide range of industrial applications …

Which of the following are commonly used magnetic materials in finishing process?

4. Which of the following material/s is/are used to hold the abrasives, in MAF? Explanation: Ferro magnetic materials hold the abrasives in order to remove material through finishing. 5.

What are the other applications where magnetic abrasive finishing can be used?

Magnetic field-assisted finishing (MAF) processes have been developed for a wide variety of applications including the manufacturing of medical components, fluid systems, optics, dies and molds, electronic components, microelectromechanical systems, and mechanical components.

Which of the following is are abrasive materials?

Explanation: An abrasive is a common ceramic material which is hard and mechanically resistant. Synthetic abrasives are preferred as they can be made as per the desired properties and also exhibit more uniformity. Diamond, sandstone, quartz, and emery are a few examples of natural abrasives.

How much is the capital equipment cost of equipment used in EBM?

How much is the capital equipment cost of equipment used in EBM? Explanation: The capital equipment cost of the Electron beam machining is high compared to other machining processes. 13. How are the production times for a material in electron beam machining?

What are the disadvantages of EBM?

Disadvantages of EBM: Limitation of EBM

  • The metal removal rate is very slow.
  • The cost of equipment is very high.
  • It is not suitable for large workpieces.
  • High skilled operators are required to operate this machine.
  • High specific energy consumption.
  • A little taper produced on holes.

Which is not disadvantage of electron beam machine?

Disadvantages of Electron Beam Machining Method The equipment costs high and operator of high skill is required for carrying out operations. It is not very suitable for sinking deep holes if the sides must be parallel.

What is the full form of LBM in advanced machining processes?

Laser Beam Machining (LBM) is one of the most popular non conventional machining processes used in the area of advanced machining. From: Modern Machining Technology, 2020.

Which of the following is disadvantage of LBM?

Disadvantages: LBM is applicable only for thin sections and where a small quantity of material is removed. Control of hole size is difficult. Holes drilled may have a slight taper formation, hence not suitable for large holes.

Which laser material is used in LBM process?

There are a number of laser types developed in the solid-state category in which Nd:YAG is majorly used for LBM applications. Solid-state lasers such as Nd:YAG, ruby and Nd-glass are highly used for machining metallic materials. Nd:YAG lasers can also be used to ceramic materials.

Which one processes is not laser?

Which of the following processes does not use lasers? Explanation: Laser Beam Machining or more broadly laser material processing deals with machining and material processing like heat treatment, alloying, cladding, sheet metal bending, etc.

Which laser is eye safe?

Lasers with emission wavelengths longer than ≈ 1.4 μm are often called “eye-safe”, because light in that wavelength range is strongly absorbed in the eye’s cornea and lens and therefore cannot reach the significantly more sensitive retina.

Which materials are used for laser processing?

Both solid and gas lasers are being used for materials processing. Solid lasers such as Nd:YAG and ruby are used for thin components while CO2 lasers are used for the thick ones. The choice of the laser for any particular application depends upon the thickness and physical properties of the material to be processed.

What are the values of current densities required in IBM?

9. What are the values of current densities required in IBM? Explanation: The value of current density of about 0.85 mA/cm2 is required for machining the work piece materials in Ion beam machining.